<div id="dialog" style="position: absolute; top: 200px; left: 50%; margin-left: -250px;">
<div id="dialogCanvas" style="padding: 10px; width: 480px; height: 180px; border: 1px solid black; background: #eee; position: relative;">
 <button class="ok" style="position: absolute; bottom: 10px; right: 120px; width: 100px;">OK</button>
 <button class="cancel" style="position: absolute; bottom: 10px; right: 10px; width: 100px;">Cancel</button>
</div>
</div>